1. Field of the Invention
The present invention relates to a water faucet. More particularly, the present invention relates to a cylinder-stem single-tap cartridge which utilizes the compression-type water tap barrel installed at the faucet.
2. Description of the Prior Art
As is well known, the water faucet is used as connected to the terminal end of a water supply pipe and designed to be operable at a maximum service pressure of 7.5 kg/cm.sup.2. As it is used in conjunction with tap water utility service, the faucet must meet the applicable specifications. For example, it has been specified that the material for the faucet barrel should be cast bronze.
Water faucets may be structurally classified into the compression type faucet in which the opening and closing action of the valve is made by the screwing of the stem bar, the plug type faucet in which the opening and closing action is effected by rotating the valve shaft through 90 degrees, the self-closing type faucet in which the valve is manually opened, with closure being effected by a spring force or water pressure, and the ball-tap faucet in which a ball acting as a float in water closes or opens the valve. Of these various types of faucets, the faucet which is most prevalently used is the compression-type faucet. This type of faucet is simple in construction, available at low cost, and least susceptible to mechanical failure but is disadvantageous in that as the packing dowel is compressed at every closing action, the useful life of the dowel is very short. Furthermore, there is the inconvenience that the stem bar must be advanced or receded along a threaded guide by means of a suitable handle or knob. To overcome the above-mentioned disadvantages of a compression type faucet, the present inventors contemplated the application of a single-lever cylinder stem construction, which is well known as the hot and cold water mixing tap from Japanese Utility Model Publication No. 56-26134 and No. 56-30785, for instance, to a single-tap water faucet. However, a single lever hot-and-cold water mixing faucet of the cylinder stem type is complicated in construction and, compared with the common compression type faucet, has the disadvantage of high production cost. On the other hand, the single-tap water faucets described in Japanese patent Publication No. 59 -34308 and Japanese Utility Model Publication No. 59-7427, for instance, utilize the barrel of the existing compression type water faucet but still have the above-mentioned drawbacks of the conventional compression-type faucet.